Insulating compound and the method of forming the same.



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UNITED STATES PATENT OFFICE,

JONATHAN W. HARRIS, OF MONTCLAIR, NEW JERSEY, ASSIGNOR, BY MESNE ASSIGN= MENTS, TO WESTERN ELECTRIC COMPANY, INCORPORATED, A CORPORATION OF NEW YORK.

Specification of Letters Patent.

Patented Sept. 18, iltbt'ih Application filed March 5, 1915. Serial No. 12,393.

To all whom it may concern:

Be it known that ll, JONATHAN W. Han- RIs, a citizen of the United States, residing at Montclair, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Insulating Compounds and the Methods of Forming the Same, of which the following is a full, clear, concise, and exact description.

This invention relates to an insulating compound and the method of forming the same.

its object is to provide for wires or other electric conductors, an elastic coating possessing high insulating properties and which ofiers high resistance to solvents, acids, alkalis and heat. The invention utilizes the desirable property of certain oils, particularly castor oil, of solidifying into an insoluble mass when subjected to destructive distillation, as set forth in United States Letters Patent No. 1,101,281, dated June 2a, 1914.

In accordance with the present invention, one or more of the metallic soaps of castor oil, or such metallic soap or soaps together with other suitable substances, are brought into combination with a suitable oil, such as castor oil, therebv producing a compound which, when subjected to destructive distillation, that is to temperature such as will result in the polymerization of the oil, will provide an insulating material having the aforementioned desirable properties.

lln the preferred manner of practising the invention, castor oil and one or more of the metallic oxids such as copper oxid, ferric oxid, aluminium oxid, or oxide of the alkaline earths, are brought into combination by heating a mixture of the oil and metallic oxid until the oxid unites with the castor oil to form the corresponding metallic soap, The temperature during this preliminary step of the process is preferably between 250 and 310 C. As is well known, castor oil when subjected to destructive distillation solidifies into an insoluble mass. The aforementioned heating is preferably continued to almost the critical point at which such solidification of the castor oil takes place. In practice, it has been found desirable that the heating of the mixture may be conother decomposition products of castor oil' have been distilled to the extent of approximately 5% to of the original volume of castor oil. A coating mixture is thus produced which, while hot, is readily soluble in such suitable solvents as turpentine, pine oil, solvent naphtha and kerosene, or mixtures of the same. The coating mixture can quickly and readily be converted, at a suitable temperature, into the insoluble solid of the castor oil, that is to a temperature apv proximating 250 to 310 C. The tempera ture is preferably about 300 C. or there about in order to expedite the process. At such temperature the complete destructive distillation and polvmerization of the coat" ing upon the wire into a solid mass takes place in from about one-half to three min utes, depending on the size of the wire. A machine especially suitable for applying and baking the insulating coating upon wire is disclosed in United States Letters Patent No. 1,004,251, dated September 26, 1911.

The finished coating is a hard, elastic, con-= tinuous, enamel-like substance, remarkably resistant to heat, organic solvents, dilute acids and alkalis.

Instead of forming the metallic soaps in. the castor oil as above described, suitable metallic soaps, previously formed, may be added to the castor oil to form the coating mixture which as before stated is prefer= ably brought as near as possible to the point of solidification before being applied to the wire or other object to be coated.

It has been found that the fossil resins or the so-called metallic resinates, or combinations of the aforementioned agents may be substituted, in whole or in part, for the metallic oxids or metallic soaps in the process and product above described. Processes and products based on these other agents form the subject-matter of other copending applications.

The proportion of castor oil and metallic oxid or metallic soaps or other of the afore-' mentioned agents may be varied at will, according to the hardness desired in the finished coating. The greater the proportion of metallic oxid or other hardening agent or agents, the harder will be the finished coating and the lower its elasticity.

What is claimed is:

1. An insulating material comprising substantially a polymerized compound of castor oil and a metallic soap.

2. An insulating coating comprising substantially castor oil and a metallic soap of castor oil subjected to destructive distillation.

3. The process of making an insulating coating which consists in heating together a mixture in which the only active ingredients are castor oil and a metallic soap of castor oil.

4. The process of making an insulating coating which consists in heating together a metallic soap and castor oil, thus forming a coating mixture, and subjecting the coating mixture thus formed, after application to the article to be coated, to a temperature sufiicient to destructively distil the castor oil and form a hard, elastic, enamel-like substance. g

5. The process of making insulating material which consists in heating a mixture composed chiefly of castor oil and a metallic soap of castor oil, and subjecting said mixture, in the form in which the insulating material is desired, to sufiicient heat to convert the mixture into a solid insoluble substance.

6. The process of making insulating material which consists in polymerizing a mixture in which the only active ingredients are castor oil and a metallic soap.

7. The process of making an insulating coating which consists in heating a mixture of castor oil and a metallic soap of castor oil to an extent approximating but short of that necessary for converting the mixture into a solid mass, and then subjecting the mixture, applied to an object to be coated, to a temperature suitable for converting the coating into a hard enamel-like substance.

8. The process of making an insulating coating which consists in heating a mixture of castor oil and a metallic soap at a tem perature approximating 250 to 310 C. until approximately 5% to 15% of the decomposition products of the castor oil has been distilled, and then subjecting the mixture, applied to the object to be coated, to a temperature of approximately 300 C.

In witness whereof, I hereunto subscribe my name this 3rd day of March, A. D. 1915.

JONATHAN W. HARRIS.

Witnesses E. .EDLER, K. L. S'rAHL. 

